Palivizumab reduces medically attended RSV infections in preterm infants, shows similar efficacy to nirsevimab

This meta-analysis pooled data from three randomized, placebo-controlled studies involving 2,464 healthy infants born at ≤35 weeks' gestational age. It evaluated palivizumab versus placebo for preventing medically attended, non-hospitalized respiratory syncytial virus infections (MARI) and RSV-related hospitalization. The setting and follow-up duration were not reported.

For the primary outcome of MARI in infants born at 29-35 weeks' gestational age, palivizumab showed a 70.5% reduction compared with placebo. The analysis also indicated that palivizumab had broadly similar efficacy to nirsevimab for preventing MARI. However, the researchers reported no absolute numbers, p-values, or confidence intervals for these efficacy estimates. RSV-related hospitalization was a secondary outcome, but specific results were not provided in the available data.

No safety, tolerability, or adverse event data were reported for palivizumab in this analysis. Key limitations include limited data specifically on palivizumab efficacy at preventing MARI and the absence of absolute effect sizes, confidence intervals, and direct comparative statistical analysis with nirsevimab (only described as 'broadly similar').

For practice, this meta-analysis suggests palivizumab may reduce medically attended RSV infections in preterm infants, with efficacy appearing comparable to nirsevimab based on limited comparative assessment. However, clinicians should note the evidence comes from a meta-analysis with significant data gaps—particularly regarding absolute risk reduction, precision of estimates, and safety information—which limits definitive conclusions about comparative effectiveness.